Rhizophora Apiculata Research Articles

PRESENCE OF FOLIAR DISEASES CAUSED BY FUNGI IN MANGROVES ON THE EAST COAST OF PENINSULAR MALAYSIA

Mangrove health is very important for the ecosystem to survive the challenges and threats due to climate change and anthropogenic pressures. However, unhealthy mangroves due to pathogenic fungi causing diseases may demote the survival rate of younger plants to grow and information on the status of foliar disease incidence is limited. This study aimed 1) to observe the foliar disease symptoms that occurred on Rhizophora apiculata and Avicennia marina and 2) to identify the fungi isolated from the symptomatic leaves. Samples were collected from the mangrove area located in Universiti Malaysia Terengganu (UMT) campus, along the South China Sea. All isolates were identified based on their morphological characteristics. A total of five foliar disease symptoms were observed namely black leaf spot, grey leaf spot, leaf rot, sunken leaf blight, and anthracnose. Rhizophora apiculata has a greater number of leaf spots than A. marina. Four genera of fungi; Pestalotiopsis sp., Curvularia sp., Colletotrichum sp. and Rhizopus sp. were successfully isolated from symptomatic leaves where the most dominant was Pestalotiopsis sp. to both mangrove species. This finding highlights the need to obtain the status of foliar diseases and their impact on the resilience of mangroves in Malaysia.

The Potential of Blue Carbon Stocks and Carbon Dioxide Absorption in Mangrove Forests to Support Low Carbon Emission Development in Southeast Sulawesi Province, Indonesia

Indonesia is a country with the second-longest coastline globally and has the most extensive mangrove forests in the world. Mangrove forests are included in the blue carbon group, which per hectare store up to four times more carbon storage than tropical forests. Mangrove forests play an essential role in absorbing carbon emissions in the air and storing a lot of carbon compared to natural forests. This study aims to determine carbon storage and CO2 absorption in mangrove forests in Kabaena Barat Subdistrict, Bombana Regency. The data comes from direct measurements in the field, namely above-ground carbon, carried out without damaging trees, only covering carbon in tree vegetation. It is the largest proportion of carbon storage on land. The data collection used a survey method to identify mangrove species, circumference, tree trunk diameter at breast height (dbh), biomass, carbon storage, CO2 absorption, and 22 plots of plotted line method with eight transects. The results showed that 10 types of mangrove species were found on the transect observation, namely Avicennia alba, Avicennia marina, Avicennia lanata, Avicennia sp., Bruguiera cylindrica, Bruguiera gymnorhiza, Rhizophora apiculata, Rhizophora mucronata, Sonneratia alba, and Xylocarpus granatum. With the total amount of biomass stored in Kabaena Barat Subdistrict's mangrove forests, Bombana Regency, is 6,664.93 tons ha-1 with carbon storage of 3,065.85 tons ha-1 and carbon dioxide absorption of 11,241.55 tons ha-1.

ASSOCIATION BETWEEN ROOT COMPLEXITY OF Rhizophora apiculata AND SEDIMENTATION AT PANTAI KELANANG, SELANGOR

Roots play important roles in tree structural adaptation and accumulation of nutrients during growth. This is particularly critical for mangrove trees that facing strong current and weak based for implantation in the sand. However, how the complexity of mangrove roots contributes to structural adaptation and affect sedimentation remains unelucidated. In this study, the complexity of Rhizophora apiculata’s roots influence the sedimentation under the root structures and at the walkway area in Pantai Kelanang, Morib were investigated. The complexity of R. apiculata pneumatophores was computationally analyzed. The sediment composition was measured using a wet-sieve method and laser diffraction method. The correlative analysis shows that no definite pattern between angles and lengths of R. apiculata roots. Assessment of sediment composition shows significant differences between walkways and under the roots. There is a high accumulation of organic matter and sand in sediment samples from under the roots. While the walkway has a high accumulation of clays and silt than others. Mathematical scoring reveals a positive association between root complexities with the accumulation of organic matters and sand in both areas. While sand and clay accumulation are inversely associated.

Effects of bioturbation of fiddler crabs in relation to the growth of mangrove saplings (Rhizophora apiculata) in a mangrove reforested area

Bioturbation is an important process in the soft-bottom ecosystem to return nutrients in the environment. This study aimed to evaluate the effects of bioturbation activities on the growth of mangrove saplings (Rhizophora apiculata). A caging experiment using a total of 16 plots each measuring 1 × 1 m containing two mangrove saplings in each plot (N=32 saplings) with eight caged and eight uncaged plots were placed randomly in Guang-guang, Davao Oriental, Philippines. The set-up was monitored for five months. The length of internode, number of nodes, leaves and length of branches of the saplings were measured and counted. In addition, the number of mounds, holes and fiddler crabs were also counted in the uncaged, marked plots to determine their activities. Result of the comparison of the number of holes, mounds, and fiddler crabs showed high significant differences with the number of holes in the sediment being greater in the uncaged set-ups (holes > mounds = fiddler crab; P<0.001). Further, the result based on t-test showed high significant differences in terms of internode length (uncaged=35.68 cm vs caged=33.19 cm; t-value=-5.15; P<0.001), number of nodes (uncaged=8.70 vs caged=6.75; t-value=-8.55; P<0.001), and branch length (uncaged=6.0 cm vs caged=5.24 cm; t-value= -2.73, P=0.008) as well as for the number of leaves (uncaged=7.12 vs caged=6.0 leaves; t-value=-4.83, P<0.001). The study concludes that bioturbation by fiddler crabs can affect the growth of saplings.

Karakteristik Kondisi Mangrove di Desa Taddan Kabupaten Sampang

Mangroves are intertidal plants found along tropical and non-tropical coastlines which is flooded by tides in brackish areas. Mangroves ecosystems have experienced a very large decrease in area especially in Madura region. This research was conducted in Taddan Village, Camplong District, Sampang. The objectives of this research were to identify mangrove vegetation, mangrove area and mangrove characteristics. The area of mangroves in the research location was 48 ha. There were 7 types of mangroves found, e.g Rhizophora apiculata, Rhizophora stylosa, Rhizophora mucronata, Sonneratia alba, Sonneratia caseolaris, Avicennia marina and Avicennia alba. The type of substrate in the mangrove research location was mainly mud. The distribution pattern of mangroves at the research location tends to spread in groups, with a low level of mangrove diversity. The uniformity index value is balanced, or in other words, there are individuals who dominate. The average sediment depth is 24.7 cm, the average salinity is 36.7 ppt, the average water pH is 5.3, the average DO is 5.9 mg / l, the average water temperature is 31, 70C, the average soil pH is 6.4. Further analysis concluded that environmental parameters in the area was unsuitable for marine tourism.

CONDITION OF MANGROVE FORESTS IN DOMPAK URBAN VILLAGE BUKIT BESTARI SUB-DISTRICT RIAU ISLAND PROVINCE

This study was conducted in December 2019, which was located in Dompak Village, Bukit Bestari District, Tanjungpinang City, Riau Islands Province. The purpose of this study was to determine the species composition and condition of mangrove forests based on the value of density, canopy cover and the importance value index of mangroves. The survey method was used in this study, where the data collected was primary data. There are 10 types of mangroves including Avicennia lanata, Bruguiera gymnorrhiza, B. cylindrica, Rhizophora apiculata, R. stylosa, Nypa fruticans, Sonneratia alba, Xylocarpus granatum, Scyphiphora hydrophyllacea and Hibiscus tiliaceus. Mangrove density was in good condition with moderate to dense ​​ranging from 1344.44-1555.56 ind/ha. Canopy cover was in good condition ​​ranging from 61.49-68.47%. The highest importance value index was R. apiculata with a value of 140.32% and the lowest was B. cylindrica with a value of 4.29%.

Characteristics of mangrove ecosystems in Weda Bay: Environment, Vegetation, and Aboveground Carbon Stocks

Weda Bay is one of the largest mangrove habitat in North Maluku and one of mega-biodiversity spots in Indonesia. However, data and information of mangrove vegetation and its ecosystem services particularly carbon stocks were limited. Mangroves were mapped using GIS-remote sensing and vegetation were sampled using transects in five sites of mangroves across Weda Bay. Tansects were extended from seaward to landward to cover all vegetation variation and hydrodynamic conditions. Environmental data (water and substrate): temperature, pH, Dissolved Oxygen (DO), particle size of sediment, and nutrient (phosphate and nitrate) were collected. The objective is to identify characteristics of mangrove landscape and vegetation, it is environment, and it ecosystem services in term of aboveground carbon stocks. The study showed that the characteristics of landscape and vegetation of mangrove varied among hydrodynamic conditions. The bay is important habitat for 8.5% (17 species) of mangrove species in Indonesia. Rhizophora apiculata and Bruguiera gymnorrhiza were the most dominant mangroves. The environmental conditions of Weda Bay particularly northern part of the bay were suitable for mangrove growth. Substrate of mangrove did not vary significantly with distance from the seaward which was mainly dominated by mud and clay (3.9 - 63 μm). Mean water temperature in the mangrove area was 29.3°C, salinity 34.1 psu, mean water suspension was 46 mg l−1, mean dissolved oxygen was 3.2 mg l−1, and water current was 10 m s−1. Aboveground carbon stock was considerable (752 ± 17.6 Mg C ha−1). Change in aboveground carbon stocks over the distance from the seaward edge to landward edge was not significantly different. In contrast, aboveground carbon stocks varied among hydrodynamic conditions: estuarine, delta, and riverine mangroves. Delta mangrove contained the highest carbon stock (993 ± 27.7 Mg C ha−1), followed by estuarine mangroves (645 ± 12.2 Mg C ha−1) and riverine mangroves (244 ± 8.6 Mg C ha−1). However, this ecosystem faced some threats such as mangrove extraction and plastic pollution. Better mangrove management e.g. reducing mangrove extraction and pollution are required to protect the functions and ecosystem services of mangroves. In addition, conserving mangrove forests will allow the government to achieve blue economy goals and to mitigate climate change through carbon sequestration.

Diversity and Long-Term Dynamics of the Macrobenthos in a Mangrove Plantation and Two Natural Associations of Khanh Hoa Province, Vietnam

The rapid decline in the area occupied by mangrove forests has convinced the Vietnamese government to launch a program for conserving and restoring the mangrove ecosystems throughout the country. This program included an experimental planting of Rhizophora apiculata seedlings in Dam Bay in Khanh Hoa province. In the course of this work, the state of the macrobenthos was monitored in new mangrove plantations, and its quantitative and qualitative characteristics were compared with those in natural mangrove associations of this area. The bulk of the material was collected in three intertidal zones in the area of ​​mangrove plantations in Dam Bay. In addition, natural mangrove associations were investigated: one in Dam Bay, and the other (the most mature and largest association of the area) in the neighboring Nha Phu Bay. The natural mangrove association in Dam Bay was represented by a narrow belt of Rhizophora apiculata. The intertidal zone in the area of ​​mangrove plantations is also represented by a narrow belt of Rhizophora apiculata. Until 2004, the middle and lower zones were formed by the mudflat. In 2004, mangrove seedlings were planted in the middle intertidal zone below the mature trees of the upper zone. As the seedlings grew, they began to slow down tidal currents, and nutrients began to linger in the ecosystem. The developing crown of young trees began to give litter and shade, favorable for the development of microalgae. In addition, young trees formed a hard substrate. As a result, there was an increase in the species diversity of the macrobenthic eurybiotic species and an increase in the abundance of opportunistic species. Young trees in the middle intertidal zone and formed a single mangrove forest of a large area together with adult trees of the upper zone, which caused the appearance of specialized species of gastropods and bivalve mollusks, as well as crabs. During the monitoring period, the composition and structure of the macrobenthos of mangrove plantations were gradually approaching to those in the mature natural mangrove association in Nha Phu. However, significant differences still remain between these associations after ten years of observing the growth of mangrove seedlings. The macrobenthos of Nha Phu is represented by a large number of specialized mangrove species of gastropod mollusks, and it also has a completely different structure of the taxocene of bivalve mollusks. This is likely explained by the high floristic diversity in Nha Phu and the maturity of this mangrove association. As a result of qualitative and quantitative collection of the macrobenthos, 139 species of invertebrates were found in the three mangrove associations studied. The key groups of the macrobenthos are gastropods, bivalve mollusks, and crabs. The data obtained on the composition and diversity of the macrobenthos fit into the general pattern of the mangrove fauna of the Indo-West Pacific and Southeast Asia.

Long-Term Heavy Metal Retention by Mangroves and Effect on Its Growth: A Field Inventory and Scenario Simulation.

The ability of mangroves in taking up and storing heavy metal (HM) helps in reducing HM pollution. However, HMs likewise adversely affect the growth of mangroves. We assess the effects of the long-term soil HMs enrichment on the growth of Rhizophora apiculata forest in the Can Gio Mangrove Forest (Southern Vietnam) in different environmental conditions of soil salinity, ground elevation, and tree density based on a novel set of measured data. These data were analyzed and were used to calibrate and validate for a tree growth model with influencing factors salinity, elevation, tree density, and heavy metals content. Three scenario simulations were performed to predict the mangrove dynamics under different levels of heavy metal pollution in combined environmental conditions of salinity and elevation. Simulation results show the decline of total forest biomass from 1,750,000 tons (baseline scenario with no HM pollution) down to 850,000 tons and 350,000 tons for the current HM pollution and double HM pollution scenarios, respectively. Both data analysis and simulations have shown that although mangroves can assist in reducing HM pollution, the quality and health of this ecosystem will be severely affected if the environment is excessively polluted. In addition, a data-and-model driven management tool is devised for the sustainable management of the mangrove environmental resources.

The Study of Mangrove Reproductive Phenology in The Rhizophoraceae Family (Bruguiera gymnorrhiza (L.) Lamk., Ceriops tagal (Perr.) C.B. Rob., Rhizophora apiculata Blume. and Rhizophora mucronata Lamk.)

Kendari Bay is directly adjacent to the Kendari City area, so that it receives a lot of pressure mainly from community activities. This pressure causes the declining of mangrove forest area every year. Reproductive phenology of mangroves can be used in planning, collecting seeds, and seeding propagules for rehabilitation of degraded mangrove forest area. The aims of this research were to know the morphological characteristics of mangrove reprodutive organs and mangrove reproductive phenology of Bruguiera gymnorrhiza, Ceriops tagal, Rhizophora apiculata, and Rhizophora mucronata in Kendari Bay. The method using in this research was observation method that conducted directly in the field. Morphology and phenology of mangrove reproduction divided into 6 phases, i.e. flower bud, blooming flower, ovary, fruit, young propagule and mature propagule. The data was analysed descriptively. According to the result, the morphological characteristics of 4 mangrove species were different. Flower of B. gymnorrhiza was single, whereas flowers of C. tagal, R. apiculata and R. mucronata were inflorescences. Ovary of B. gymnorrhiza was hemi inferous, whereas ovaries of C. tagal, R. apiculata and R. mucronata were superous. R. mucronata had the largest propagule compared to other mangroves observed. The timing of mangrove reproductive phenology also showed different result. B. gymnorrhiza required 299 days to develop from flower bud to mature propagule and R. apiculata required 262 days, whereas C. tagal and R. mucronata  had not been able known its phenological period because the timing data from ovary to fruit had not been obtained. Further research is needed to resolve this issue.ÂÂ

Famili Rhizophoraceae di Hutan Mangrove KKPD Rupat Utara Provinsi Riau Bagian I, Deskripsi Anggota

Pemantauan kekayaan spesies mangrove sangat diperlukan dalam merumuskan suatu pengelolaan dan konservasi mangrove, sehingga kajian deskripsi angota-anggota famili Rhizophoraceae dilakukan pada bulan Juli 2018 di hutan mangrove KKPD Rupat Utara. Kajian ini bertujuan untuk mengeksplorasi anggota famili Rhizophoraceae yang menyusun hutan mangrove KKPD Rupat Utara dan juga bertujuan sebagai data dasar dalam mengevaluasi ekosistem mangrove KKPD Rupat Utara dikemudian harinya. Metode yang digunakan adalah transek garis dan jelajah. Hal ini bermaksud agar spesimen yang dikumpulkan menjadi lebih lengkap. Sebanyak 5 spesies anggota Rhizophoraceae teridentifikasi sebagai penyusun hutan mangrove KKPD Rupat Utara yaitu Bruguiera gymnorrhiza, B. sexangula, Ceriops tagal, Rhizophora apiculata dan R. mucronata.

Low genetic diversity indicating the threatened status of Rhizophora apiculata (Rhizophoraceae) in Malaysia: declined evolution meets habitat destruction

Worldwide, many mangrove species are experiencing significant population declines, including Rhizophora apiculata, which is one of the most widespread and economically important species in tropical Asia. In Malaysia, there has been an alarming decline in R. apiculata populations driven primarily by anthropogenic activities. However, the lack of genetic and demographic information on this species has hampered local efforts to conserve it. To address these gaps, we generated novel genetic information for R. apiculata, based on 1,120 samples collected from 39 natural populations in Peninsular Malaysia. We investigated its genetic diversity and genetic structure with 19 transcriptome and three nuclear microsatellite markers. Our analyses revealed a low genetic diversity (mean He: 0.352) with significant genetic differentiation (FST: 0.315) among populations of R. apiculata. Approximately two-third of the populations showed significant excess of homozygotes, indicating persistent inbreeding which might be due to the decrease in population size or fragmentation. From the cluster analyses, the populations investigated were divided into two distinct clusters, comprising the west and east coasts of Peninsular Malaysia. The western cluster was further divided into two sub-clusters with one of the sub-clusters showing strong admixture pattern that harbours high levels of genetic diversity, thus deserving high priority for conservation.

Inhibitory effect of Malaysian coastal plants on banana (Musa acuminata colla "Lakatan"), ginger (Zingiber officinale Roscoe) and sweet potato (Ipomoea batatas) polyphenol oxidase.

Undesired browning reaction catalyzed by polyphenol oxidase (PPO) has reduced the nutritional quality and customer acceptance of the products. The inhibitory effects of six coastal plants including Sonneratia alba, Rhizophora apiculata, Syzygium grande, Rhizophora mucronata, Hibiscus tiliaceus and Bruguiera gymnorhiza on PPO in banana, sweet potato and ginger were studied based on oxidation of pyrocatechol. Banana exhibited the highest PPO activity (141,600 U), followed by sweet potato (43,440 U) and ginger (26,880 U). Banana PPO was strongly inhibited by R. apiculata (70.87%) and sweet potato PPO was strongly inhibited by S. alba (82.00%). In general, most banana PPO was the most susceptible to inhibition with all inhibitors having inhibition higher than 60.00% at 0.5mg/ml and ginger PPO was the least susceptible with all inhibitors showing less than 50.00% inhibition at 0.5mg/ml. Coastal plant extracts are potentially to be developed as natural inhibitors for preventing enzymatic browning of fruits and vegetables.

Important value aspect of mangrove community at coastal area of Pangkalpinang City, Bangka Island

Mangrove is a one of high - level plants becouse it has structure roots, branches and leafes. Mangrove commonly was found in the delta or brakishwater, but has ecological benefit as well as economic value. Mangrove found in the intertidal zone and high tide level. This research was aimed to analysis important value aspect of species mangroves at coastal area of Pangkalpinang City. This study uses a purposive sampling method. Data was collected using the line and plot transect method (LTP) and hemisphere photography agreed upon for mangrove monitoring in the COREMAP-CTI. The results showed that Mangrove composition found in 5 stations as many as 22 species mangroves which were classified into 10 family Rhizophoraceae, Sonneratiaceae, Avicenniaceae, Meliaceae, Combretaceae, Rubiaceae, Euphorbiaceae, Myrcinaceae, Arecaceae, Malvaceae, Pteridaceae. The type of vegetation that has the highest INP value at the capling level is Rhizophora apiculata BI. of 266.65%, and The type of vegetation that has the highest INP value at the sapling level is Rhizophora apiculata BI. of 202.85%. Dominance species found in 5 station is Rhizophora apiculata BI and Sonneratia alba.

Tingkat kerusakan ekosistem mangrove di Kawasan Estuari Sei Jang Kecamatan Bukit Bestari Kota Tanjungpinang, Kepulauan Riau, Indonesia

Research on the level of damage to mangrove ecosystems has been carried out in Estuarine Area Sei Jang. The purpose of this study was to determine the types of mangroves, the density and percentage of mangrove canopy cover, and the level of damage to mangrove ecosystems in the Sei Jang Estuary Area of Tanjung Pinang City. This research was conducted in March 2019. Determination of the research location using a purposive sampling method of 3 stations and using a 10 x 10 m transect for the density and percentage of mangrove canopy cover. The results found four types of mangroves namely Bruguiera gymnorhiza, Rhizophora apiculata, Rhizophora mucronata, and Ceriops tagal with density values (1.033-1.367 individu/ha) and the percentage of mangrove canopy cover with values (61.55-78.41%). For the level of damage at Station I and III are categorized (good) and Station II is categorized (Damaged).

Physicochemical factors influencing zonation patterns, niche width and tolerances of dominant mangroves in southern Oriental Mindoro, Philippines

Abstract. Raganas AFM, Magcale-Macandog DBM. 2020. Physicochemical factors influencing zonation patterns, niche width, and tolerances of dominant mangroves in southern Oriental Mindoro, Philippines. Ocean Life 4: 51-62. Physicochemical factors are known for having strong influence on the spatial patterns and structural complexity of mangroves. In this regard, we aimed to contribute to filling up this information gap in the six mangrove ecosystems on the southern coast of Oriental Mindoro, Philippines. In each of the six mangrove ecosystems, the dominant mangrove species were identified in four mangrove zones - seaward, riverine, middle, and landward - using a stratified random sampling method for vegetation survey. Physicochemical parameters of water, air, and soil were also obtained from these ecozones. Results of the Principal Component Analysis revealed that temperature and water salinity are the factors that show strong influence on the spatial distribution of the dominant mangrove species. Canonical Correspondence Analysis revealed that Avicennia marina, Sonneratia alba, and Rhizophora apiculata, are species associated with a highly saline environment, while Xylocarpus granatum, Ceriops decandra, Avicennia rumphiana, and Rhizophora mucronata are species associated with low to optimum saline environment. Most of these dominant species preferred ecotypes with low to optimum salinity levels as revealed by their individual niche width and tolerances. The different adaptations and dominance of these mangrove species provide insights in the identification of appropriate species that could be used as planting materials for rehabilitation endeavors in the respective mangrove ecosystem.

Sebaran spesies dan status kerapatan ekosistem mangrove di pesisir Kabupaten Muna Barat, Sulawesi Tenggara

Mangrove merupakan ekosistem pesisir yang sangat penting bagi manusia karena memiliki fungsi ekonomi, fisik, dan ekologi. Salah satu wilayah pesisir yang merupakan habitat ekosistem mangove adalah pesisir Kabupaten Muna Barat. Adanya pembangunan berdampak pada pengurangan luas dan kerapatan ekosistem mangrove sehingga mempengaruhi struktur dan status kerapatan ekosistem mangrove. Jumlah spesies mangrove yang ada di pesisir Kabupaten Muna Barat adalah sepuluh spesies yang terdiri Bruguiera cylindrica, Bruguiera gymnorrhiza, Rhizophora mucronata, Rhizophora apiculata, Rhizophora stylosa, Sonneratia alba, Xylocarpus granatum, Ceriops tagal, Scyphiphora hydrophyllacea, dan Calophyllum inophyllum. Total kerapatan mangrove adalah 752 pohon/ha yang terdiri dari 879 pohon/ha pada stasiun I, 621 pohon/ha pada stasiun II, 687 pohon/ha pada stasiun III, dan 820 pohon/ha pada stasiun IV dengan status kerapatan termasuk pada kategori rendah.

Effect of biochar and compost application on nitrogen dynamics in organically managed nutrient-poor paddy soil system and in organic rice cultivation system

Nitrogen (N) is an essential plant nutrient, and its retention in the soil is beneficial to plant growth and productivity. High levels of N can leach from soil with organic amendments, particularly in water-rich paddy rice cultivation. Biochar has the potential to influence the soil N cycle. The study included four treatments applied to organically managed nutrient-poor paddy soil (S) and rice cultivation (R) systems, respectively over two growing seasons: biochar only (BA), compost only (CA), biochar and compost mixed at an equal rate (BC), and no amendment (control). Biochar produced from mangrove (Rhizophora apiculata) which obtained from slow pyrolysis in a traditional kiln, whereas compost generated from organic municipal solid waste. The results showed that, on average, BA and BC maintained NO3--N and NH4+-N in the soil and reduced absolute N leaching compared to the control and CA, respectively. System R maintained nitrogen better than system S. BA reduced N mass leaching by 27.25% in system S and by 59.21% in system R, compared to the control, while BC reduced N mass leaching by 24.85% in system S and by 58.48% in system R, compared to CA. However, the reduction in N2O emission fluxes was not significant in both BA and BC in both seasons, although cumulative emission fluxes after a year of cultivation decreased significantly. BC significantly boosted water use efficiency relative to yield in system R. These results show that co-application of biochar and compost to nutrient-poor soil in an organically managed system substantially reduced N leaching and suggests that it could be an effective management option for organic rice cultivation in Thailand. Keywords: Biochar, compost, nitrogen leaching, N2O emmision, nitrogen balance, organic rice cultivation.

Growth analysis of mangrove (Rhizophora apiculata bl) propagule toward differences in types of water and planting media at Makassar mangrove center

Mangrove cultivation is currently hard to find due to many aspects that needed to be observed. The success of mangrove to grow and develop from seeds, nursery, and planting are depending on water salinity and mangroves planting media. The objectives of this study were to investigate the planting media, water types, as well as the combination of planting media and water used, which were the best for mangrove’s growth. The method used in this study was an experimental field approach with a Complete Randomized Design (SRD) factorial experiment and Duncan’s Multiple Range Test as its posthoc test. The growing media used were mud and mud added with compost in a ratio 1:1, and the water types used for watering were seawater, freshwater, and the mixture of seawater and fresh water in a ratio 1:1. The observation variables in this study included the increase of propagule height (measurement from cotyledon’s neck up to the tips of plant shoots), an increase in diameter, and percentages of growing propagules. Watering with freshwater showed the most significant increase in height and diameter of propagules. Meanwhile, for planting media, the most appropriate one was mud added with compost. For treatment combinations, the combination of freshwater with mud added with compost provided a better effect on propagule growth. However, all of the combinations had shown growth.

Struktur dan Asosiasi Vegetasi Mangrove di Hilir DAS Torue, Parigi Moutong, Sulawesi Tengah (Structure and Association of Mangrove Vegetation in Torue Watershed Downstream, Parigi Moutong, Central Sulawesi)

One important aspect needed in mangrove forest management was the data and information available regarding structure and associations. However, the structure and association of mangrove forests in the Torue watershed downstream had not been identified. The purpose of this research was to evaluate the structure and association of mangrove forests in the Torue watershed downstream. This research used the plot path method with a path and plot combination. Path placement was done by purposive sampling. The results showed that the mangrove forest structure of the Torue watershed downstream consisted of three canopy layers, i.e., Stratum C, D, and E, which were dominated by seedling and sapling growth rates. Stratum C was dominated by Sonneratia alba type, and Stratum D was dominated by Bruguiera gymnorizha and Bruguiera sexangula types. In contrast, Stratum E was dominated by Rhizophora mucronata and Rhizophora apiculata types. There was no association between mangrove vegetation and all species. However, three pairs of species had a positive association coefficient, namely: Sonneratia alba with Rhizophora apiculata with a coefficient value of 0,42, Rhizophora mucronata with Bruguiera gymnorhiza, and Rhizophora mucronata with Bruguiera sexangula each coefficient value of 0,06, which was not associated with five species, namely Sonneratia alba, Rhizophora mucronata, Rhizophora apiculata, Bruguiera gymnorizha, and Bruguiera sexangula. The results of this study could be the basis of the guidelines for sustainability in mangrove forest management.Keywords: association, mangrove forest, vegetation structure, watershed